Why it matters on your quote
Manual J tells you how much heating and cooling a home needs. Manual S uses manufacturer performance data to choose equipment that meets that load in your climate, rather than simply picking the nearest nominal size. Manual D sizes the ducts so the chosen equipment gets the airflow it needs.
A quote that mentions J, S and D describes a designed system. Most replacements reuse existing ducts, so it is reasonable to ask whether the ducts were checked against the new equipment's airflow.